沼液喷淋秸秆与生物炭联合好氧发酵效果研究

为实现沼液的减量化和肥料化,以玉米秸秆为载体吸附过滤沼液,开展沼液喷淋与秸秆和生物炭联合好氧发酵试验,分析沼液喷淋对好氧发酵效果的影响,以及与秸秆和生物炭共发酵的效果。结果表明,粉碎后玉米秸秆吸附过滤猪粪沼液、鸡粪沼液后,秸秆含水率由5.92%分别上升至76.35%和85.72%,碳氮比由42.4分别上升至50.2和51.7,沼液中总悬浮物、总磷分别降低了34.42%～43.78%和20.00%～41.01%,而对溶解态的总磷、总钾吸附过滤效果一般。沼液喷淋翻拋可延长堆体发酵高温期2倍时长以上,有机质含量降低了10.42%～18.63%,氮磷钾含量提高6%～21.5%左右,并可提高堆体腐熟度,促进类腐殖质物质产生。添加生物炭可缩短发酵升温期并延长高温期,更有利于堆体消纳沼液。沼液喷淋与秸秆和生物炭联合好氧发酵工艺可达到利用沼液生产有机肥的目的,是资源化利用沼液的有效途径之一。

Effect of corn stalk and biochar aerobic fermentation combined with biogas slurry spraying

Abstract: At present, the demand for the quantitative reduction and resources recovery of biogas slurry is increasing rapidly. In this study, an aerobic fermentation experiment of biogas slurry with biochar and corn stalks after adsorbing and filtering the biogas slurry, was conducted to investigate the effect of biogas slurry spraying to the fermentation, and the effect of co-fermentation with corn straw and biochar was also analyzed. The results indicated that crushed corn straws had better water absorbing ability and suspended matter filtering ability. Moisture content of crushed corn straws, after adsorbing and filtering the biogas slurry of pig manure and chicken manure, increased from 5.92% to 76.35% and 85.72%, and the carbon nitrogen ratio increased from 42.4 to 50.2 and 51.7, respectively. Due to the effect of corn stalks adsorption filtration, total suspended matter and total phosphorus in the biogas slurry of pig manure and chicken manure decreased 34.42%-43.78% and 20.00%-41.01%, respectively. The adsorption and filtering effects of crushed corn stalks to the total phosphorus and total potassium were not significant in slurry. After adsorption saturation, carbon nitrogen ratio of corn stalks was not suitable for aerobic fermentation, indicating amendments were important assistant materials in the composting process. Biogas slurry spraying and compost turning could prolong the duration of high temperature phase more than 2 times during fermentation. The addition of biochar to the compost could shorten the temperature raising period and prolong the high temperature period, which could be benefit of utilizing biogas slurry. The content of nitrogen, phosphorus and potassium were found to increase constantly in the composting process. After aerobic fermentation, organic matter content of fermentation materials with slurry spraying decreased by 10.42%-18.63% and the total contents of nitrogen, phosphorus and potassium increased by 6%~21.5% compared to other treatments without slurry spraying. The compost maturity of fermentation materials with slurry spraying was also improved. The test results demonstrated that the technology of corn stalk and biochar aerobic fermentation combined with biogas slurry spraying could be feasible to make use of quantitative reduction and resources recovery of biogas slurry to produce organic fertilizer, which had better environmental, social and economic benefits. Meanwhile, there are some further studies are needed to conduct. Firstly, process parameter optimization of the technology in the paper will be needed. Secondly, the effect of different amount of biochar added to the compost still needs further study. Thirdly, the technology in the paper is more suitable for gutter fermentation process, and the related process parameters worth in-depth study.